Pediatrics Resident Ann & Robert H. Lurie Children's Hospital of Chicago Chicago, Illinois, United States
Background: Chorioamnionitis (chorio) refers to intraamniotic inflammation/infection and is associated with neonatal morbidity. Clinical chorio aligns only moderately with histologic chorio, yet mothers and infants often receive lab work-up and antibiotics. Histopathology results require processing and expert interpretation, often beyond the timeframe to impact initial clinical care decisions. Microbiologic diagnosis by amniotic fluid culture is also delayed. Rapid placental techniques may optimize antibiotic-decision making in the setting of clinical chorio. Objective: To determine the bacterial DNA load of placental membranes by real-time quantitative PCR among pregnancies with and without clinical chorio and histologic chorio. Design/Methods: Fifty-two placentas from full-term deliveries were included in this case-control study (n=25 clinical chorio, n=27 controls). The study was approved (exempt) by the Northwestern University IRB. Clinical data collection from the medical record into REDCap database includes pregnancy and infant data (GBS status, prolonged rupture of membranes, lab results, maternal fever, neonatal hospital course). Placental samples were formalin fixed, placed in paraffin blocks, and underwent histopathologic analysis with grading of maternal and fetal inflammatory response (Amsterdam criteria, 0-3 scale). Biopsy specimens of chorion and amniotic membrane (near the point of rupture) were obtained, weighed, and stored at -80°C. DNA was isolated from 70-80mg of each sample. A broad range real-time PCR (TaqMan) targeting a conserved region of 16S rRNA gene will be used to quantify total bacteria DNA load. Standard curve and positive controls spiked with known concentrations of E. coli will be run. The Mann-Whitney rank sum test will be used to compare CT values to determine if bacterial DNA load is significantly higher in samples from patients with clinical chorio and/or histologic chorio. Currently clinical data collection, placental histology, and DNA extraction is complete. TaqMan qPCR assays are currently in process.
